See? If we're facing South then West is right and it's still true in the Real world.
Nice picture. Now draw me one where I said that east in Terraria is to the right.
East is to the right of anyone facing north. Period. We can't tell if Terraria's camera faces north or south, so it's reasonable to assume for now that it faces south, since south is to the right of where east is and the goblin army message seems to mean 'left' when it says 'east'. Check your picture for directions.
What the Tinkerer says is completely irrelevant in and out of the game, since he just mentions the reason for which he was tied up. The goblins could confuse east and west constantly, which would make them right half of the time, or they could have switched directions a few times during the long journey from wherever they came from. Not to mention that the game itself tells you which way the goblins are coming from, so it doesn't even matter what the goblins themselves think. They're not telling you.
Once again: My argument is that
east is 90° to the right of north. There's no sure way to tell whether Terraria is right or wrong about it's cardinal directions unless we know 100% which direction the background is. If any fictional place assumes that east is to the left of north, despite being consistent about it, it is wrong.
Stop thinking I disagree with you about the cardinal directions. I disagree with citing in-game sources as correct.